Radio communication has become an integral aspect of everyday life in modern society, with a broad range of possible applications. Regardless of the application, clear communication between radio transmitters and radio receivers may be desired. Clear radio communication may depend on a number of factors including, for example, signal strength, noise introduced by a transmitter/receiver device, and interference power within wireless communication channels through which wireless signals are communicated.
In radio receiver circuit designs, high amplifier gain linearity and minimal noise figures are desirable to meet certain design requirements so as to enable clear radio communications, for example. Noise is an undesirable product of electronic devices and components. One metric for noise figures is a noise factor, which is a measure of how much noise is introduced into a signal being amplified during an amplification process. A noise factor can be a ratio of a signal-to-noise ratio (SNR) of an input signal to the SNR of the amplified output signal. Other sources of noise to consider include input thermal noise in the receiver circuit as well as quantization noise of analog-to-digital converters (ADC) in the receiver circuit, for example. To enable clear radio communications, noise levels are to be lowered.
Radio receivers are often designed to meet a worst case scenario for received signal strength, noise of the devices, and interference power. For example, a receiver is usually designed to be able to receive/decode a signal with a weak signal-strength during high interference conditions. However, it is often the case that conditions are not that bad when operating the receiver. For example, a worst-case scenario may occur a small portion of the time when operating the receiver, and it is more likely that better than worst-case conditions are present a majority of the time. As such, over-design of receiver components is common and results in a waste of power operating the receiver when channel conditions are more benign. This presents an area where power optimization can be improved.